1. Field of the Invention
The present invention relates to a printer having a function for printing to both sides of cut-sheet forms and other print media. The invention further relates to a control method for controlling the printer and to a data medium for having a computer program to implement the control method.
More particularly, the present invention relates to a printer for handling a print medium, such as a personal check, having a predefined format with specific front and back sides to which different information must be appropriately printed. The invention further relates to a control method for controlling the printer and to a data storage medium for storing said control method.
2. Description of the Related Art
Printers for printing to such specifically formatted printing forms as invoices, tickets, and personal or corporate checks are widely available and commonly used. Typical of such printers are point-of-sale (POS) printers for printing sales receipts as well as customer checks received for payment. A typical check processing method used in a POS system is described below.
A basic POS system comprises a host device and a printer connected to this host. The printer comprises a print head for check printing and a MICR (magnetic ink character recognition) head for reading magnetic ink characters preprinted to the check.
The characters and print quality of MICR text conforms to known standards such as E13B or CMC7. MICR text is also printed to a standardized location on the checks. When the MICR head passes over the MICR text, the text is detected and converted to an electrical signal. The waveform of the signal varies with each letter, thereby making it possible to interpret the signal to recognize and read the preprinted MICR text.
Check processing at the POS station includes printing the date, store name, and check amount on the check front, and printing a check endorsement and bank account number for the store on the back. For simplicity below, these operations are hereafter referred to as simply printing the front and back of the check.
FIG. 19 is a flow chart of a check processing method using a conventional printer comprised to read MICR text when the check is inserted for printing the back of the check.
When a store clerk receives a check for payment from a customer, the clerk operates the host to receive payment via check. This causes the host device to start check processing, and send a MICR text reading command to the printer. The printer thus receives and interprets this read command, and waits for a check to be inserted so that the read command can be executed (step S1901).
When the clerk inserts a check to the printer, the printer reads and recognizes the MICR text (step S1902), and sends the result to the host (step S1903). The host then determines whether the check is valid based on the information received from the printer. Check validation in this example can be simply accomplished by comparing the checking account number read from the check with a database of invalid account numbers.
If the check is determined to be valid, the host sends the information for printing for the back of the check to the printer. Note that this information is hereafter referred to as the endorsement information. When the printer receives the endorsement information (step S1904), it advances the check to the printing start position of the print head (step S1905), prints (step S1906), and then ejects the printed check (step S1907).
The clerk then turns the check over and reinserts to the printer. The printer again advances the check to the printing start position (step S1908). When the check is positioned, the host sends the information to be printed on the check front, referred to as the payment information below, to the printer. The printer thus receives the payment information (step S1909), prints (step S1910), and ejects the printed check (step S1911). The clerk then hands the printed check to the customer for verification and signing, and receives the check back from the customer to complete the transaction.
It will thus be obvious that a conventional printer of this type prints to both sides of a check or other standard form by printing data in the sequence received from the host, printing a first set of information to one side of the form, waiting for the operator to reverse and reinsert the form, and then printing a second set of information to the other side of the form.
Conventional printers of the type described above, however, are unable to determine whether the print data received from the host is to be printed to the front or to the back of the form. The printer therefore prints whatever data is received from the host to whichever side of the form is inserted for printing, regardless of whether the form is appropriately positioned for printing to the desired side. This means that if the form is incorrectly inserted and positioned, the printing process still executes. This results in inconvenience for both the operator and customer and unnecessarily wastes blank forms or checks
Furthermore, while some printers have the print head and the MICR head positioned on the same side of the form transportation path, other printers have these heads on opposite sides of the form transportation path. The host must therefore change the sequence in which data is sent to the printer based on whether these heads are on the same or opposite sides of the path. That is, the host must be set up or switch to send either the form front information, i.e., the payment information in the above example, or the form back information, i.e., the endorsement information in the above example, first, and this further complicates the printing process.
Therefore, it is an object of the present invention to overcome the aforementioned problems.
With consideration for the above-described problems, it is therefore an object of the present invention to provide a printer for correctly printing print data to a desired side of a print form.
It is a further object of the present invention to provide a control method for this printer.
It is yet further object of the present invention to provide a medium for having a computer program implementing the control method.
To achieve the above objects, a printer connected to a host device for printing to a print medium based on print data and a print command received from the host device comprises according to the present invention: a print command interpreter for interpreting print commands from the host device and determining a print medium side indicated by a received print command for printing associated print data; an inserted side detection processor or detecting means for detecting which side of a print medium inserted to the printer is facing a particular direction; and a control unit for printing the print data when the print medium side detected by the print command interpreter and the print medium side detected by the inserted side detecting means are the same.
Printing to the wrong side of a print medium (form) can thus be prevented because printing occurs when the print medium side specified by the host and the side of the print medium inserted for printing are the same.
Further preferably, the control unit causes the inserted print medium to be ejected when the print medium side detected by the print command interpreter and the print medium side detected by the inserted side detecting means are not the same.
In this case the printer further preferably comprises a form insertion opening for inserting a print medium, and a form ejection opening for ejecting a print medium from the printer. Yet further preferably, the control unit causes the inserted print medium to be ejected from the form ejection opening after printing is completed when the print medium side detected by the print command interpreter and the print medium side detected by the inserted side detection processor or detecting means are the same, and causes the inserted print medium to be ejected from the form insertion opening when the print medium side detected by the print command interpreter and the print medium side detected by the inserted side detecting means are not the same.
By thus differently ejecting the print medium, the printer operator can easily determine whether printing was completed normally.
Yet further preferably, a printer according to the present invention additionally comprises a form reversing mechanism for reversing sides of an inserted print medium. When thus comprised, the control unit reverses print medium sides by means of the form reversing mechanism, and then prints the print data to the print medium, when the print medium side detected by the print command interpreter and the print medium side detected by the inserted side detecting means are not the same.
By thus reversing sides of the print medium when the print medium is not inserted to the printer with the side specified for printing by the host correctly oriented for printing, the printer can automatically match the printed side of the medium to the side specified by the host. Desired printing results can therefore be achieved, and printer throughput and productivity can be improved.
Alternatively, a printer according to the present invention comprises a first printing unit for printing print data to one side of a print medium, and a second printing unit for printing print data to the other side of a print medium. In this case the control unit selects the first or second printing unit for printing received print data to the print medium side indicated by the print command based on the print medium side detected by the print command interpreter and the print medium side detected by the inserted side detecting means.
Desirable printing results can thus be reliably achieved even when the print medium is not inserted to the printer with the side specified for printing by the host desirably oriented for printing because the printer selectively drives one of two printing units based on the side indicated by the host device and the orientation of the inserted print medium.
Further alternatively, a printer according to the present invention comprises an inserted form side notification unit or inserted form side notification means for sending to the host device a print medium side notification indicative of the print medium side detected by the inserted side detection processor or detecting means, and a print data receiver or receiving means for receiving from the host device print data corresponding to the detected print medium side. In this case the control unit prints the received print data to the print medium.
By thus requesting print data corresponding to a specific side of the print medium, desired printing results can be achieved even when printing buffer capacity is limited.
Yet further alternatively, a printer according to the present invention comprises a first storage buffer for storing print data for printing to a front side of the print medium, and a second storage buffer for storing print data for printing to a back side of the print medium. The control unit in this case selects data stored to the first or second storage buffer and prints to the print medium based on the print medium side detected by the inserted side detecting means.
Printing errors can thus be prevented and efficiency can be improved because print data is retrieved from a buffer corresponding to a particular side of the print medium. It is therefore possible to repeatedly use the same print data when print data is static. As a result, steps for resending the same print data multiple times can be eliminated.
A printer according to the present invention further preferably comprises an insertion direction detection processor or detecting means for detecting a direction in which a print medium is inserted to the printer, and a print data rotation processor or print data rotation processing means for rotating print data based on the form insertion direction detected by the insertion direction detection processor or detecting means.
When thus comprised, print data can be processed for both the form side inserted for printing and the lengthwise or widthwise orientation of the inserted form.
The inserted side detection processor or detecting means and insertion direction detector or detecting means can respectively detect which side of the print medium is inserted for printing and the lengthwise or widthwise orientation of the inserted form by detecting a specific marking on the print medium. Exemplary markings include magnetic ink characters and bar codes.
It is also possible to use a print medium having one or more specific corners cut off. In this case the inserted side detection processor or detecting means and insertion direction detector or detecting means can respectively function by detecting the specific corner(s).
It will also be obvious that the present invention can be expressed as a method for controlling a printer, and this method can achieve the same advantages and benefits described above. In addition, a control method according to the present invention can be provided as a control program that can be run by a control unit for the printer. This control program can also be provided by way of a medium to which the control program is recorded and stored. Exemplary storage media include: semiconductor memory, CD-ROM, floppy disk, hard disk, magneto-optical disk, DVD-ROM and DVD-RAM disks, and magnetic tape. Such storage media can also be used to introduce a control program according to the present invention to existing printers. This control program can also be made available on an internal computer network or an external computer network, such as a site on the World Wide Web, enabling users to download the program for use with existing printers.